# -*- coding=utf-8 -*-
from __future__ import absolute_import, unicode_literals
import itertools
import re
import shlex
__all__ = ["ScriptEmptyError", "Script"]
[docs]class ScriptEmptyError(ValueError):
pass
def _quote_if_contains(value, pattern):
if next(re.finditer(pattern, value), None):
return '"{0}"'.format(re.sub(r'(\\*)"', r'\1\1\\"', value))
return value
[docs]class Script(object):
"""Parse a script line (in Pipfile's [scripts] section).
This always works in POSIX mode, even on Windows.
"""
def __init__(self, command, args=None):
self._parts = [command]
if args:
self._parts.extend(args)
[docs] @classmethod
def parse(cls, value):
if isinstance(value, str):
value = shlex.split(value)
if not value:
raise ScriptEmptyError(value)
return cls(value[0], value[1:])
def __repr__(self):
return "Script({0!r})".format(self._parts)
@property
def command(self):
return self._parts[0]
@property
def args(self):
return self._parts[1:]
[docs] def extend(self, extra_args):
self._parts.extend(extra_args)
[docs] def cmdify(self):
"""Encode into a cmd-executable string.
This re-implements CreateProcess's quoting logic to turn a list of
arguments into one single string for the shell to interpret.
* All double quotes are escaped with a backslash.
* Existing backslashes before a quote are doubled, so they are all
escaped properly.
* Backslashes elsewhere are left as-is; cmd will interpret them
literally.
The result is then quoted into a pair of double quotes to be grouped.
An argument is intentionally not quoted if it does not contain
whitespaces. This is done to be compatible with Windows built-in
commands that don't work well with quotes, e.g. everything with `echo`,
and DOS-style (forward slash) switches.
The intended use of this function is to pre-process an argument list
before passing it into ``subprocess.Popen(..., shell=True)``.
See also: https://docs.python.org/3/library/subprocess.html#converting-argument-sequence
"""
return " ".join(
itertools.chain(
[_quote_if_contains(self.command, r"[\s^()]")],
(_quote_if_contains(arg, r"[\s^]") for arg in self.args),
)
)